rTMS at harmonics of biological signals

ABSTRACT

Repetitive Transcranial Magnetic Stimulation (rTMS) is administered at a pulse rate that is equal to or a harmonic of a biological metric of a patient. The purpose is to provide frequency coupling among different organs (e.g., heart, brain, breathing, and gastrointestinal movement) through rhythmic entrainment. The specific harmonic chosen is the one closest to a desired EEG frequency. The desired EEG frequency is chosen based on the cognitive element or symptom that is targeted.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of co-pendingapplication Ser. No. 13/858,693, filed on Apr. 8, 2013; which claims thebenefit of U.S. Provisional Application Ser. No. 61/621,423, filed onApr. 6, 2012, the disclosure of which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to methods of modulating brain activitywith repetitive transcranial magnetic stimulation (rTMS) wherein therTMS is administered at a frequency of a biological metric or a harmonicof a biological metric.

BACKGROUND OF THE INVENTION

Transcranial magnetic stimulation and rTMS have been used to treat manypsychological and medical disorders such as major depressive disorder,Parkinson's disease, Alzheimer's disease, autism spectrum disorder(ASD), schizophrenia and others. Recently, Jin and Phillips, in USPatent Publication 2009/0082690, have disclosed a treatment protocolusing rTMS where the output of the magnetic field is adjusted based on apatient's EEG intrinsic frequencies in an attempt to alter the patient'sintrinsic EEG frequencies.

SUMMARY OF THE INVENTION

Briefly, in accordance with the present invention the brain activity ofa mammal is modulated by subjecting the mammal to repetitivetranscranial magnetic stimulation (rTMS) at a frequency of a biologicalmetric, or a harmonic (including sub-harmonics) of the biological metricfor a time sufficient to modulate the brain activity of the mammal. Animprovement in a physiological condition, psychological condition, or aneuropsychiatric condition exhibited by the mammal is achieved. Thebiological metric can be any biological metric including but not limitedto heart rate, respiratory rate, gastrointestinal movement rate, or anEEG frequency. Preferably, the brain activity to be modulated is adesired EEG band, such as, for example, the brains' alpha waves, and therTMS frequency is equal to, or a harmonic or sub-harmonic of, a non-EEGbiological metric that is closest to the targeted frequency in a desiredEEG band such as for example the heart rate, which is a sub-harmonic ofthe alpha frequency. Other biological metrics include the patient'srespiratory rate and the gastrointestinal movement rate (rate ofperistalsis). Other EEG frequencies include the delta band (<4 Hz), thetheta band (4-8 Hz), the beta band (13-30 Hz), the gamma band (˜40 Hz)or the Mu band (8-13 Hz).

By modulating the brain activity of a mammal, improvements in physicalconditions, psychological conditions, and neuropsychiatric conditionsare improved in a non-invasive manner and usually without the need formedications. Physical conditions that can be improved include painrelief (pain management), blood pressure, stress, libido, motorfunction, physical performance, height (in children) or weight.Psychological conditions that can be improved includedconcentration/focus, sleep, alertness, memory, speech, intelligence, andother cognitive functions. Neuropsychiatric conditions that can beimproved include symptoms of Autism Spectrum Disorder (ASD), Alzheimer'sdisease, attention deficit hyperactivity disorder (ADHD), schizophrenia,anxiety, depression, coma, Parkinson's disease, substance abuse, bipolardisorder, a sleep disorder, an eating disorder, tinnitus, traumaticbrain injury, post traumatic stress disorder (PTSD), or fibromyalgia.

Of particular interest in the practice of the present invention aremethods of modulating a human patient's alpha brain waves in a patientwith ASD, chronic pain or Alzheimer's disease. The rTMS treatmentprotocol will begin as a daily regimen of 30 minutes of rTMS set at afrequency which is a harmonic of the patient's heart rate which isclosest to the frequency in the alpha brain wave range of 8-13 Hz. Asseen in Example 1 below, if the patient's heart rate is 1.5 Hz then the6^(th) harmonic will be set a treatment frequency of the rTMS device at9 Hz where his alpha EEG frequency may be at 9.1 Hz or 8.9 Hz. Eachpatient will vary depending on his/her specific biological measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows coherence between the alpha band and the heart rate.

FIG. 2 shows coherence between the delta band and the heart rate.

DETAILED DESCRIPTION OF THE INVENTION

The term “mammal” when used herein includes any mammal especiallyhumans. Non-human mammals include non-human primates, zoo animals,companion animals (dogs, cats), performance mammals such as race horseand breeding animals.

Various bodily functions operate at frequencies that are harmonics orsub-harmonics of the brain's intrinsic frequency. For example, the heartrate is approximately the 6^(th), 7th, 8^(th), or 9^(th) sub-harmonic ofthe brain's alpha frequency at awake and the 2^(nd) or 3^(rd)sub-harmonic of delta at sleep. The breathing rate is generally the5^(th) sub-harmonic of the heartbeat. The gastrointestinal movementfrequency is approximately the 4^(th) or 5^(th) sub-harmonic of thebreathing rate.

It is evident that it is advantageous for there to be coherence betweenthe peak frequency of a dominant EEG activity and the nearest higherharmonic of a biological metric such as for example the resting heartrate. In various disease states coherence is low while in healthy statescoherence is high. In a preferred embodiment of the present inventionthe frequency of an administered rTMS treatment is chosen according tothe EEG peak frequency that has the highest coherence coefficient withthe EEG.

FIG. 1 shows a patient's alpha band EEG pattern in the upper leftportion (top 3 patterns) with a corresponding fast Fourier transform(FFT) appearing to the right of each pattern showing frequency peaks.The bottom left pattern is an electrocardiogram (ECG) pattern of thesame patient with the corresponding higher harmonics appearing to theright of the ECG pattern. The coherence coefficient is shown in a box tothe right side of the EEG graphs. The highest coherence coefficient ofthe alpha peak frequency with the 9^(th) harmonic of the heart rate canbe seen from the top EEG pattern (Coh=0.6). The 9^(th) harmonic of theheart rate is 10.52 Hz and this is the preferred frequency for thispatient's rTMS treatment for conditions such as chronic pain, ASD andAlzheimer's disease.

FIG. 2 shows a patient's delta band EEG pattern in the upper leftportion (top 3 patterns) with a corresponding fast Fourier transform(FFT) appearing to the right of each pattern showing frequency peaks.The bottom left pattern is an electrocardiogram (ECG) pattern of thesame patient with the corresponding higher harmonics appearing to theright of the ECG pattern. The coherence coefficient is shown in a box tothe right side of the EEG graphs. The highest coherence coefficient ofthe delta band peak frequency with the 3^(rd) harmonic of the heart ratecan be seen from the bottom EEG pattern (Coh=0.7). The 3rd harmonic ofthe heart rate is 3.69 Hz and this is the preferred frequency for thispatient's rTMS treatment for conditions such as insomnia and attentiondeficit disorders.

A desynchronized oscillatory system amongst the organs is less energyefficient. The frequency coupling among different organs develops byrhythmic entrainment in order to lower the total energy cost andincrease efficiency of the system as a whole. Patients with variousmental disorders are often found to have frequency “decoupling” betweencritical organs, such as heart and brain. Providing rTMS at thefrequency (or a harmonic thereof) of one of these biological signals canmake use of the body's natural resonance to influence brain activity andresynchronize the heart/brain/respiratory/gastro oscillation, lowerenergy, and increase efficiency and stability. This in turn will lessenthe symptoms of the disorder or improve a physical condition which, inthe case of Alzheimer's disease and ASD, results in improved cognitivefunction and motor function associated with movement or speech.Additionally, in underdeveloped children rTMS treatments according tothe present invention may increase the height and weight of the treatedchild. In another embodiment of the present invention, chronic painrelief can be achieved by administering rTMS to a patient in chronicpain at a frequency that is a harmonic of the patient's heart ratepreferably the 6^(th)-10^(th) harmonic of the heart rate.

By providing rTMS stimulation to the brain at a harmonic of theheartbeat, breathing rate, or gastrointestinal frequency, entrainmentand the resonant property of the mammalian system will gradually improvethe frequency coupling among organs. The brain is targeted because it isthe central control mechanism for all organs in the body. The frequencychosen is preferably a harmonic of the heartbeat that is closest to aninterested frequency that may be associated with the disorder, symptom,cognitive characteristic or physical condition of interest. Frequenciesof interest include the following:

-   -   a. Delta band intrinsic frequency (<4 Hz). Delta waves are        normally prevalent in infants, during slow wave sleep or during        continuous attention tasks in adults. In pathological        conditions, it is often associated with metabolic encephalopathy        or other types diffused brain lesions. In general, rTMS at        2^(nd) or 3^(rd) harmonic of heartbeat are used to treat        insomnia and improve attention.    -   b. Theta band intrinsic frequency (4-8 Hz). Theta waves are        commonly found in children and during periods of drowsiness in        adults. It is also associated with inhibition of elicited        responses. It has been observed in pathological conditions such        as focal subcortical lesions, metabolic encephalopathy, and deep        midline disorders. In general, rTMS at 4^(th) or 5^(th) harmonic        of heartbeat may help control impulsive behavior in autism and        many other mental disorders    -   c. Alpha band intrinsic frequency (8-13 Hz). Alpha band is        normally found during periods of relaxation while closing the        eyes. Physiologically it is associated with the process of        inhibition control. Lack of alpha activity is found in autism,        and other mental disorders, such as anxiety, schizophrenia, and        ADHD. Reduced alpha frequency coherence has been found in        patients with Alzheimer's disease. Excessive alpha activity may        be seen in comatose conditions. In general, rTMS in this range        will help treat autism, reduce anxiety, increase attention, or        treat schizophrenia and Alzheimer's.    -   d. Beta band intrinsic frequency (13-30 Hz). Beta band is        associated with alertness, busy or anxious thinking. Significant        reduction of beta activity is often found in subjects treated        with benzodiazepines. rTMS in this range will help to increase        alertness.    -   e. Gamma band intrinsic frequency (˜40 Hz). Gamma activity        displays during cross-modal sensory processing or short term        memory matching of recognized objects, sounds, or tactile        sensations. A decrease in gamma band activity may be associated        with cognitive decline, such as Alzheimer's disease. rTMS in        this range is used to treat cognitive deficits in Alzheimer's        disease or other forms of dementia.    -   f. Mu activity (8-13 Hz). Mu rhythm has frequency overlap with        alpha wave but, instead of parietal occipital regions, it is        only seen in the sensory motor cortex. It reflects the        synchronous firing of motor neurons in rest state. Mu        suppression is thought to reflect motor mirror neuron systems.        Deficits in Mu suppression, and thus in motor neurons, play a        role in autism. rTMS in the frequency band at the specific        location will help normalize the mirror neurons to treat autism.

In a preferred embodiment of the present invention, an harmonic of apatient's heart rate is used to determine the rTMS frequency in apatient where the alpha brain wave frequency cannot be determined orwhich is poorly defined. An harmonic of the heart rate is chosen whichmost closely corresponds to a frequency within the alpha brain waveintrinsic frequency of 8-13 Hz. If the intrinsic alpha brain wavefrequency of an autistic patient or an Alzheimer's patient cannot bedetermined or is ill-defined then an harmonic of the heart rate ischosen which is within the 8-13 Hz range. The patient is then treatedwith rTMS at that harmonic and the patient is monitored with EEG todetermine when an intrinsic alpha brain wave frequency emerges. Then therTMS frequency can be changed to this frequency if it is different thanthe original harmonic used. For example, if an autistic patient has aheart rate of 1.5 Hz and the patient's intrinsic alpha brain wavescannot be determined then the rTMS treatments are initially set to the6^(th) harmonic or 9 Hz. The patient is treated at this frequency untilan intrinsic alpha brain wave frequency is established. rTMS treatmentsare then continued at the intrinsic frequency.

The following Table 1 shows examples of the present invention where rTMSis used to modify alpha brain waves (intrinsic frequency 8-13 Hz). Table1 shows the heart rate, the heart frequency in Hz and a frequency of therTMS treatment. Typically the rTMS output intensity used to treat apatient is from 10% to about 120% of the motor threshold of the patient.

TABLE 1 Heart Rate (beat/min) Heart Rate in Hz rTMS Frequncy in Hz 500.83 9.96 60 1.0 9.0 65 1.08 8.64 70 1.17 11.7 75 1.25 11.25 80 1.3310.64 85 1.42 11.36 90 1.5 9.0

The following Table 2 shows examples of the present invention where rTMSis used to modify delta brain waves (intrinsic frequency <4 Hz). Table 2shows the heart rate, the heart frequency in Hz and a frequency of therTMS treatment. Typically the rTMS power used to treat a patient is from10% to about 120% of the motor threshold of the patient.

TABLE 2 Heart Rate (beat/min) Heart Rate in Hz rTMS Frequncy in Hz 500.83 2.49 60 1.0 3.0 65 1.08 2.16 70 1.17 3.51 75 1.25 2.50 80 1.33 2.6685 1.42 2.84 90 1.5 3.0

The following Table 3 shows examples of the present invention where rTMSis used to modify theta brain waves (intrinsic frequency 4-8 Hz). Table3 shows the heart rate, the heart frequency in Hz and a frequency of therTMS treatment. Typically the rTMS power used to treat a patient is from10% to about 120% of the motor threshold of the patient.

TABLE 3 Heart Rate (beat/min) Heart Rate in Hz rTMS Frequncy in Hz 500.83 4.98 60 1.0 6.0 65 1.08 7.56 70 1.17 5.85 75 1.25 5.0 80 1.33 6.6585 1.42 4.26 90 1.5 4.5

The following Table 4 shows examples of the present invention where rTMSis used to modify beta brain waves (intrinsic frequency 13-30 Hz). Table4 shows the heart rate, the heart frequency in Hz and a frequency of therTMS treatment. Typically the rTMS power used to treat a patient is from10% to about 120% of the motor threshold of the patient.

TABLE 4 rTMS Frequncy in Hz Heart Rate (beat/min) Heart Rate in Hz (85%of Motor Threshhold) 50 0.83 20.7 60 1.0 32.0 65 1.08 19.44 70 1.1732.76 75 1.25 25.0 80 1.33 15.96 85 1.42 31.24 90 1.5 30.0

The following Table 5 shows examples of the present invention where rTMSis used to modify gamma waves (intrinsic frequency ˜40 Hz). Table 5shows the heart rate, the heartfrequency in Hz and a frequency of therTMS treatment. Typically the rTMS power used to treat a patient is from10% to about 120% of the motor threshold of the patient.

TABLE 5 Heart Rate (beat/min)  Heart Rate in Hz  rTMS Frequncy in Hz  500.83 41.5 60 1.0 54 65 1.08 75.6 70 1.17 70.2 75 1.25 50.0 80 1.33 62.5185 1.42 71.0 90 1.5 58.5

The following Table 6 shows examples of the present invention where rTMSis used to modify Mu brain waves of the sensory motor cortex (intrinsicfrequency 8-13 Hz). Table 6 shows the heart rate, the heart frequency inHz and a frequency of the rTMS treatment. Typically the rTMS power usedto treat a patient is from 10% to about 120% of the motor threshold ofthe patient.

TABLE 6 Heart Rate (beat/min) Heart Rate in Hz rTMS Frequncy in Hz 500.83 9.13 60 1.0 10.00 65 1.08 8.64 70 1.17 11.7 75 1.25 12.5 80 1.3310.64 85 1.42 8.52 90 1.5 10.5

The following example illustrates the practice of the present inventionbut should not be construed as limiting its scope.

EXAMPLE 1 Treatment of Autism

A 9 year-old boy suffered from development delay in cognitive and finemotor functions, and had been diagnosed with autism. During the initialinterview, the patient appeared to be slow in response to simplequestions, exhibited a limited working memory and had obvious difficultyin writing and other fine motor functions. The patient was reported tohave frequent head drops and improper gazing. He had been treated withanticonvulsants and was taking anticonvulsant medications. The patient'sEEG showed diffused and left-frontal lobe dominant slow waves at 6.3 Hzwith occasional short bursts of alpha rhythm in the occipital area butno clear and consistent intrinsic alpha frequency could be identified.Single-lead ECG showed a regular heartbeat at 1.5 Hz. Taking its 6^(th)higher harmonic, it was decided to set the rTMS at 9.0 Hz over themid-central and left frontal lobe. Following the first 2 sessions ofrTMS, the patient showed some degree of improvement with more vigilanceand spontaneous communication. With further treatments there was asignificant reduction of the slow waves in the patient's EEG and anincrease in alpha rhythm. Clinically, the frequency of seizure episodesreduced significantly. After titrating down the anticonvulsant dosageover time, the patient experienced a significant improvement incognitive and motor functions.

EXAMPLE 2 Pain Relief-Pain Management

An adult male had chronic pain for several years after going throughmany back surgeries. The patient's EEG showed desynchronized alpha wavesand a low alpha wave value. Single-lead ECG showed a regular heartbeatat 1 Hz. Taking its 9^(th) higher harmonic, it was decided to set therTMS at 9 Hz over the bilateral pre-frontal lobe. Following 3 sessionsof rTMS, the patient showed a significant reduction in pain. The EEGpattern showed significant improvement in alpha synchronization.

EXAMPLE 3 Treatment of Alzheimer's Disease

An adult female (85 years old) had been diagnosed with Alzheimer'sdisease for about 15 years. The patient's EEG showed alpha peakfrequency below 8 Hz which is in the theta band range. Single-lead ECGshowed a regular heartbeat at 1.2 Hz. Taking its 7^(th) higher harmonic,it was decided to set the rTMS at 8.4 Hz over the bilateral pre-frontallobe. Following 1 session of rTMS, the patient showed a significantimprovement in short term memory and working memory. After 2 weeks ofdaily (Monday-Friday) rTMS sessions the patient became more coherent andher MMSE score improved from 14 pre-treatment to 21 post treatment. TheEEG pattern showed an alpha wave near 8 Hz.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

I claim:
 1. A method of improving a physiological condition or aneuropsychiatric condition of a mammal which comprises subjecting themammal to repetitive transcranial magnetic stimulation (rTMS) at afrequency of a non-EEG biological metric, or an harmonic or sub-harmonicof said non-EEG biological metric, wherein the mammal is a human.
 2. Themethod of claim 1 wherein the non-EEG biological metric is heart rate,respiratory rate, gastrointestinal movement rate.
 3. The method of claim1 wherein the rTMS frequency is equal to, or a harmonic or sub-harmonicof, a non-EEG biological metric that is closest to an intrinsicfrequency in a desired EEG band.
 4. The method of claim 3 wherein thenon-EEG biological metric is heart rate.
 5. The method of claim 1wherein the physiological condition is concentration, sleep, alertness,memory, blood pressure, stress, libido, speech, motor function, physicalperformance, cognitive function, intelligence, height or weight.
 6. Themethod of claim 1 wherein the neuropsychiatric condition is AutismSpectrum Disorder (ASD), Alzheimer's disease, ADHD, schizophrenia,anxiety, depression, coma, Parkinson's disease, substance abuse, bipolardisorder, a sleep disorder, an eating disorder, tinnitus, traumaticbrain injury, post traumatic stress syndrome, chronic pain orfibromyalgia.
 7. The method of claim 3 wherein the intrinsic frequencyis in the delta band (<4 Hz), the theta band (4-8 Hz), the alpha band(8-13 Hz), the beta band (13-30 Hz), the gamma band (25-100 Hz), or theMu band (8-13 Hz).
 8. A method of improving the symptoms of a humanhaving autism spectrum disorder (ASD) that comprises subjecting theperson to repetitive transcranial magnetic stimulation (rTMS) at afrequency of a non-EEG biological metric, or an harmonic or sub-harmonicof said non-EEG biological metric.
 9. The method of claim 8 wherein thenon-EEG biological metric is the patient's heart rate.
 10. A method ofimproving the symptoms of a human having Alzheimer's disease thatcomprises subjecting the person to repetitive transcranial magneticstimulation (rTMS) at a frequency of a non-EEG biological metric, or anharmonic or sub-harmonic of said non-EEG biological metric.
 11. Themethod of claim 10 wherein the non-EEG biological metric is thepatient's heart rate.
 12. A method of improving the symptoms of a humanhaving chronic pain that comprises subjecting the person to repetitivetranscranial magnetic stimulation (rTMS) at a frequency of a non-EEGbiological metric, or an harmonic or sub-harmonic of said non-EEGbiological metric.
 13. The method of claim 12 wherein the non-EEGbiological metric is the patient's heart rate.
 14. The method of claim1, wherein the rTMS frequency is equal to, or a harmonic or sub-harmonicof, a non-EEG biological metric having a highest coherence coefficientto an intrinsic frequency in a desired EEG band.
 15. The method claim 8,wherein the rTMS frequency is equal to, or a harmonic or sub-harmonicof, a non-EEG biological metric having a highest coherence coefficientto an intrinsic frequency in a desired EEG band.
 16. The method of claim10, wherein the rTMS frequency is equal to, or a harmonic orsub-harmonic of, a non-EEG biological metric having a highest coherencecoefficient to an intrinsic frequency in a desired EEG band.
 17. Themethod of claim 12, wherein the rTMS frequency is equal to, or aharmonic or sub-harmonic of, a non-EEG biological metric having ahighest coherence coefficient to an intrinsic frequency in a desired EEGband.